There are several reason for doing backups of any kind. The main two seem to
be:

1) recovery in case of a drive death
2) archiving, to let you recover deleted information, take snapshots etc

The first of these issues can, to a certain extent, be covered by having a
disk raid system.... but even that doesn't solve the disater situation
(fire, flood etc)

The second issue is a way of either allowing you to recover accidentally
changed / deleted data, as well as allowing you to "snap-shot" your data (as
is often needed for legal reasons), and that sort of thing.

Of course, there are 2 aspects of the backup: "protecting" your operating
system & software, and "protecting" your data... its all very well having a
great data backup, that lets you recover al your data in 2 hours flat, if
(because of bad documentation or whatever) it takes you 3 days to correctly
re-install the underlying software!!!!!

From what I have seen (we have recently intslled a tape system that uses
ArcServe) tape backup has NOT really improved in the last 15 years: the
software is still very slow, very cumbersome, and still not easy & obvious
to use.

The next thing to ask is "what alternatives to tape are there": and as
others have said, there is only ONE that has enough capacity: hard disks!
CDR's are ok for small amounts of data (eg data on a personal computer,
rather than a server), but are nowhere near big enough or "good enough" for
(longer-term) backups of large amounts of data.

As well as needing backup where I work, I am involved with a hospital radio
station, where we have a computer playout system: the work needed to recover
all the music an associated data is huge, so it HAS to be backed up: in this
case, both PCs have a small HD with the OS & software on (which we have
ghosted onto CD, and can rebuild the pc in about 10 mins flat!), and a big
HD for the music in a caddy. One of the PC's also has a spare caddy, where
we plug in a second hd & copy all data to it: that HD is kept off-site. In
this case, we have no need for keeping archives.


I think there is still very much a place for tapes, mainly for longer-term
data archiving of large amounts of data.


Paul





"idunno" wrote in message
...
I think I'm missing something, but why do people use tape for backups?
It seems very costly and slow.

I can imagine two benefits from tape, though. The backup cartridge is
not nearly as fragile as say a hard disk and is therefore better to
transport offsite. Some better tape formats and tape libraries can
backup vast quantities of data easily and unattended.

I've been using hard disks in removable racks & external cases as well
as DVD-R. I've had bad experiences with travan a few years ago and
I've hear bad things about DAT reliability. I've been thinking about
implementing VXA or DLT based backup in a small office, but I'm having
a difficult time justifying the cost. These drives and the tapes are
quite pricey esp. if these tapes can only be used a limited number of
times. I am very worried about various nuisances with the media or
drive heads resulting from daily backups.

Sorry if my newbiness is showing. What am I missing here? How
exactly are the costs justified? For whom is tape backup best suited?